Is there an peekable similar to peekable but in additional allowing one to put some data to it?

[Peng Yu]

Hi, peekable from more-itertools only allow peeking an iterator. But
sometimes, one may want to take a look at an element, manipulate it,
then put it back to the iterator. Is there a class in python that can
help do this?

https://pypi.python.org/pypi/more-itertools/

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Regards,
Peng